Quartic scroll.tif

56(Baker No. 84) Quartic scroll with two nodal straight lines

This is the ruled surface generated by the ellipse at the top (or bottom) and the two perpendicular straight lines in the middle.Each line contains two generators of the surface (one for each point where it could intersect the ellipse), and so is a line of double points (nodes) on the surface. This model was constructed by Baker.